I recently saw a closed post for Random Loot in Raids/Dungeons which prompted me to add my two cents worth.
This is by no means a 'nerd-rage', just an observation/suggestion.
Random indicates an equal chance for an Item (loot) to drop, no one item has a higher % to drop when the Loot Table is generated.

That being a given.. the % or drop rates we see on Wow-Head, for example, is a tabulation of what 'has' dropped.
Not exactly the same thing, and definately (sp) "Not" what the in-game RNG is.
I have recently seen ~16 boss drops, 4 of which were usable by the raid group.. the others were DE'd for Maelstrom Crystals with one
BoE making it to the Auction House. Does that seem 'Random'?
No.. it does not appear random, however.. It Is Random.

I'm sure it has been suggested in the past and yes, going to put the bug back into the ear of Blizzard:
When you enter a dungeon/raid read into the Loot Table that is being generated the composition of the raid.
Tailor the possible drops to that of the raid composition so the loot is more likely to be usable to the raid as far as upgrades,
that is the reason we raid correct?
Progression.

Maybe in the future, (near), the Raid Leader will have to 'queue' the "Loot Table" and then actually start the instance.
This along with reading the raid composition would allow raiders to get what they are actually after and Maelstrom Crystals
more of an option.

Manq da Crank Tank